crypto/dh/dh_ameth.c

   1 /*
   2  * Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include <openssl/x509.h>
  13 #include <openssl/asn1.h>
  14 #include "dh_local.h"
  15 #include <openssl/bn.h>
  16 #include "crypto/asn1.h"
  17 #include "crypto/evp.h"
  18 #include <openssl/cms.h>
  19 #include <openssl/core_names.h>
  20 #include "internal/param_build.h"
  21
  22 /*
  23  * i2d/d2i like DH parameter functions which use the appropriate routine for
  24  * PKCS#3 DH or X9.42 DH.
  25  */
  26
  27 static DH *d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp,
  28                    long length)
  29 {
  30     if (pkey->ameth == &dhx_asn1_meth)
  31         return d2i_DHxparams(NULL, pp, length);
  32     return d2i_DHparams(NULL, pp, length);
  33 }
  34
  35 static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
  36 {
  37     if (pkey->ameth == &dhx_asn1_meth)
  38         return i2d_DHxparams(a, pp);
  39     return i2d_DHparams(a, pp);
  40 }
  41
  42 static void int_dh_free(EVP_PKEY *pkey)
  43 {
  44     DH_free(pkey->pkey.dh);
  45 }
  46
  47 static int dh_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
  48 {
  49     const unsigned char *p, *pm;
  50     int pklen, pmlen;
  51     int ptype;
  52     const void *pval;
  53     const ASN1_STRING *pstr;
  54     X509_ALGOR *palg;
  55     ASN1_INTEGER *public_key = NULL;
  56
  57     DH *dh = NULL;
  58
  59     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
  60         return 0;
  61     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
  62
  63     if (ptype != V_ASN1_SEQUENCE) {
  64         DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
  65         goto err;
  66     }
  67
  68     pstr = pval;
  69     pm = pstr->data;
  70     pmlen = pstr->length;
  71
  72     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
  73         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  74         goto err;
  75     }
  76
  77     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
  78         DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
  79         goto err;
  80     }
  81
  82     /* We have parameters now set public key */
  83     if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
  84         DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
  85         goto err;
  86     }
  87
  88     ASN1_INTEGER_free(public_key);
  89     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
  90     return 1;
  91
  92  err:
  93     ASN1_INTEGER_free(public_key);
  94     DH_free(dh);
  95     return 0;
  96
  97 }
  98
  99 static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 100 {
 101     DH *dh;
 102     int ptype;
 103     unsigned char *penc = NULL;
 104     int penclen;
 105     ASN1_STRING *str;
 106     ASN1_INTEGER *pub_key = NULL;
 107
 108     dh = pkey->pkey.dh;
 109
 110     str = ASN1_STRING_new();
 111     if (str == NULL) {
 112         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 113         goto err;
 114     }
 115     str->length = i2d_dhp(pkey, dh, &str->data);
 116     if (str->length <= 0) {
 117         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 118         goto err;
 119     }
 120     ptype = V_ASN1_SEQUENCE;
 121
 122     pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
 123     if (pub_key == NULL)
 124         goto err;
 125
 126     penclen = i2d_ASN1_INTEGER(pub_key, &penc);
 127
 128     ASN1_INTEGER_free(pub_key);
 129
 130     if (penclen <= 0) {
 131         DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 132         goto err;
 133     }
 134
 135     if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 136                                ptype, str, penc, penclen))
 137         return 1;
 138
 139  err:
 140     OPENSSL_free(penc);
 141     ASN1_STRING_free(str);
 142
 143     return 0;
 144 }
 145
 146 /*
 147  * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
 148  * the AlgorithmIdentifier contains the parameters, the private key is
 149  * explicitly included and the pubkey must be recalculated.
 150  */
 151
 152 static int dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 153 {
 154     const unsigned char *p, *pm;
 155     int pklen, pmlen;
 156     int ptype;
 157     const void *pval;
 158     const ASN1_STRING *pstr;
 159     const X509_ALGOR *palg;
 160     ASN1_INTEGER *privkey = NULL;
 161     DH *dh = NULL;
 162
 163     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
 164         return 0;
 165
 166     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
 167
 168     if (ptype != V_ASN1_SEQUENCE)
 169         goto decerr;
 170     if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
 171         goto decerr;
 172
 173     pstr = pval;
 174     pm = pstr->data;
 175     pmlen = pstr->length;
 176     if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
 177         goto decerr;
 178
 179     /* We have parameters now set private key */
 180     if ((dh->priv_key = BN_secure_new()) == NULL
 181         || !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
 182         DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
 183         goto dherr;
 184     }
 185     /* Calculate public key, increments dirty_cnt */
 186     if (!DH_generate_key(dh))
 187         goto dherr;
 188
 189     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 190
 191     ASN1_STRING_clear_free(privkey);
 192
 193     return 1;
 194
 195  decerr:
 196     DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
 197  dherr:
 198     DH_free(dh);
 199     ASN1_STRING_clear_free(privkey);
 200     return 0;
 201 }
 202
 203 static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 204 {
 205     ASN1_STRING *params = NULL;
 206     ASN1_INTEGER *prkey = NULL;
 207     unsigned char *dp = NULL;
 208     int dplen;
 209
 210     params = ASN1_STRING_new();
 211
 212     if (params == NULL) {
 213         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 214         goto err;
 215     }
 216
 217     params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
 218     if (params->length <= 0) {
 219         DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 220         goto err;
 221     }
 222     params->type = V_ASN1_SEQUENCE;
 223
 224     /* Get private key into integer */
 225     prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
 226
 227     if (prkey == NULL) {
 228         DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
 229         goto err;
 230     }
 231
 232     dplen = i2d_ASN1_INTEGER(prkey, &dp);
 233
 234     ASN1_STRING_clear_free(prkey);
 235     prkey = NULL;
 236
 237     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 238                          V_ASN1_SEQUENCE, params, dp, dplen))
 239         goto err;
 240
 241     return 1;
 242
 243  err:
 244     OPENSSL_free(dp);
 245     ASN1_STRING_free(params);
 246     ASN1_STRING_clear_free(prkey);
 247     return 0;
 248 }
 249
 250 static int dh_param_decode(EVP_PKEY *pkey,
 251                            const unsigned char **pder, int derlen)
 252 {
 253     DH *dh;
 254
 255     if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL) {
 256         DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
 257         return 0;
 258     }
 259     dh->dirty_cnt++;
 260     EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
 261     return 1;
 262 }
 263
 264 static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
 265 {
 266     return i2d_dhp(pkey, pkey->pkey.dh, pder);
 267 }
 268
 269 static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
 270 {
 271     int reason = ERR_R_BUF_LIB;
 272     const char *ktype = NULL;
 273     BIGNUM *priv_key, *pub_key;
 274
 275     if (ptype == 2)
 276         priv_key = x->priv_key;
 277     else
 278         priv_key = NULL;
 279
 280     if (ptype > 0)
 281         pub_key = x->pub_key;
 282     else
 283         pub_key = NULL;
 284
 285     if (x->p == NULL || (ptype == 2 && priv_key == NULL)
 286             || (ptype > 0 && pub_key == NULL)) {
 287         reason = ERR_R_PASSED_NULL_PARAMETER;
 288         goto err;
 289     }
 290
 291     if (ptype == 2)
 292         ktype = "DH Private-Key";
 293     else if (ptype == 1)
 294         ktype = "DH Public-Key";
 295     else
 296         ktype = "DH Parameters";
 297
 298     BIO_indent(bp, indent, 128);
 299     if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
 300         goto err;
 301     indent += 4;
 302
 303     if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
 304         goto err;
 305     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
 306         goto err;
 307
 308     if (!ASN1_bn_print(bp, "prime:", x->p, NULL, indent))
 309         goto err;
 310     if (!ASN1_bn_print(bp, "generator:", x->g, NULL, indent))
 311         goto err;
 312     if (x->q && !ASN1_bn_print(bp, "subgroup order:", x->q, NULL, indent))
 313         goto err;
 314     if (x->j && !ASN1_bn_print(bp, "subgroup factor:", x->j, NULL, indent))
 315         goto err;
 316     if (x->seed) {
 317         int i;
 318         BIO_indent(bp, indent, 128);
 319         BIO_puts(bp, "seed:");
 320         for (i = 0; i < x->seedlen; i++) {
 321             if ((i % 15) == 0) {
 322                 if (BIO_puts(bp, "\n") <= 0
 323                     || !BIO_indent(bp, indent + 4, 128))
 324                     goto err;
 325             }
 326             if (BIO_printf(bp, "%02x%s", x->seed[i],
 327                            ((i + 1) == x->seedlen) ? "" : ":") <= 0)
 328                 goto err;
 329         }
 330         if (BIO_write(bp, "\n", 1) <= 0)
 331             return 0;
 332     }
 333     if (x->counter && !ASN1_bn_print(bp, "counter:", x->counter, NULL, indent))
 334         goto err;
 335     if (x->length != 0) {
 336         BIO_indent(bp, indent, 128);
 337         if (BIO_printf(bp, "recommended-private-length: %d bits\n",
 338                        (int)x->length) <= 0)
 339             goto err;
 340     }
 341
 342     return 1;
 343
 344  err:
 345     DHerr(DH_F_DO_DH_PRINT, reason);
 346     return 0;
 347 }
 348
 349 static int int_dh_size(const EVP_PKEY *pkey)
 350 {
 351     return DH_size(pkey->pkey.dh);
 352 }
 353
 354 static int dh_bits(const EVP_PKEY *pkey)
 355 {
 356     return BN_num_bits(pkey->pkey.dh->p);
 357 }
 358
 359 static int dh_security_bits(const EVP_PKEY *pkey)
 360 {
 361     return DH_security_bits(pkey->pkey.dh);
 362 }
 363
 364 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 365 {
 366     if (BN_cmp(a->pkey.dh->p, b->pkey.dh->p) ||
 367         BN_cmp(a->pkey.dh->g, b->pkey.dh->g))
 368         return 0;
 369     else if (a->ameth == &dhx_asn1_meth) {
 370         if (BN_cmp(a->pkey.dh->q, b->pkey.dh->q))
 371             return 0;
 372     }
 373     return 1;
 374 }
 375
 376 static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
 377 {
 378     BIGNUM *a;
 379
 380     /*
 381      * If source is read only just copy the pointer, so
 382      * we don't have to reallocate it.
 383      */
 384     if (src == NULL)
 385         a = NULL;
 386     else if (BN_get_flags(src, BN_FLG_STATIC_DATA)
 387                 && !BN_get_flags(src, BN_FLG_MALLOCED))
 388         a = (BIGNUM *)src;
 389     else if ((a = BN_dup(src)) == NULL)
 390         return 0;
 391     BN_clear_free(*dst);
 392     *dst = a;
 393     return 1;
 394 }
 395
 396 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 397 {
 398     if (is_x942 == -1)
 399         is_x942 = ! !from->q;
 400     if (!int_dh_bn_cpy(&to->p, from->p))
 401         return 0;
 402     if (!int_dh_bn_cpy(&to->g, from->g))
 403         return 0;
 404     if (is_x942) {
 405         if (!int_dh_bn_cpy(&to->q, from->q))
 406             return 0;
 407         if (!int_dh_bn_cpy(&to->j, from->j))
 408             return 0;
 409         OPENSSL_free(to->seed);
 410         to->seed = NULL;
 411         to->seedlen = 0;
 412         if (from->seed) {
 413             to->seed = OPENSSL_memdup(from->seed, from->seedlen);
 414             if (!to->seed)
 415                 return 0;
 416             to->seedlen = from->seedlen;
 417         }
 418     } else
 419         to->length = from->length;
 420     to->dirty_cnt++;
 421     return 1;
 422 }
 423
 424 DH *DHparams_dup(const DH *dh)
 425 {
 426     DH *ret;
 427     ret = DH_new();
 428     if (ret == NULL)
 429         return NULL;
 430     if (!int_dh_param_copy(ret, dh, -1)) {
 431         DH_free(ret);
 432         return NULL;
 433     }
 434     return ret;
 435 }
 436
 437 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 438 {
 439     if (to->pkey.dh == NULL) {
 440         to->pkey.dh = DH_new();
 441         if (to->pkey.dh == NULL)
 442             return 0;
 443     }
 444     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
 445                              from->ameth == &dhx_asn1_meth);
 446 }
 447
 448 static int dh_missing_parameters(const EVP_PKEY *a)
 449 {
 450     if (a->pkey.dh == NULL || a->pkey.dh->p == NULL || a->pkey.dh->g == NULL)
 451         return 1;
 452     return 0;
 453 }
 454
 455 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 456 {
 457     if (dh_cmp_parameters(a, b) == 0)
 458         return 0;
 459     if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
 460         return 0;
 461     else
 462         return 1;
 463 }
 464
 465 static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 466                           ASN1_PCTX *ctx)
 467 {
 468     return do_dh_print(bp, pkey->pkey.dh, indent, 0);
 469 }
 470
 471 static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 472                            ASN1_PCTX *ctx)
 473 {
 474     return do_dh_print(bp, pkey->pkey.dh, indent, 1);
 475 }
 476
 477 static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 478                             ASN1_PCTX *ctx)
 479 {
 480     return do_dh_print(bp, pkey->pkey.dh, indent, 2);
 481 }
 482
 483 int DHparams_print(BIO *bp, const DH *x)
 484 {
 485     return do_dh_print(bp, x, 4, 0);
 486 }
 487
 488 #ifndef OPENSSL_NO_CMS
 489 static int dh_cms_decrypt(CMS_RecipientInfo *ri);
 490 static int dh_cms_encrypt(CMS_RecipientInfo *ri);
 491 #endif
 492
 493 static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 494 {
 495     switch (op) {
 496     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 497         return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
 498     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 499         return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2);
 500     default:
 501         return -2;
 502     }
 503 }
 504
 505 static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 506 {
 507     switch (op) {
 508 #ifndef OPENSSL_NO_CMS
 509
 510     case ASN1_PKEY_CTRL_CMS_ENVELOPE:
 511         if (arg1 == 1)
 512             return dh_cms_decrypt(arg2);
 513         else if (arg1 == 0)
 514             return dh_cms_encrypt(arg2);
 515         return -2;
 516
 517     case ASN1_PKEY_CTRL_CMS_RI_TYPE:
 518         *(int *)arg2 = CMS_RECIPINFO_AGREE;
 519         return 1;
 520 #endif
 521     default:
 522         return -2;
 523     }
 524
 525 }
 526
 527 static int dh_pkey_public_check(const EVP_PKEY *pkey)
 528 {
 529     DH *dh = pkey->pkey.dh;
 530
 531     if (dh->pub_key == NULL) {
 532         DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
 533         return 0;
 534     }
 535
 536     return DH_check_pub_key_ex(dh, dh->pub_key);
 537 }
 538
 539 static int dh_pkey_param_check(const EVP_PKEY *pkey)
 540 {
 541     DH *dh = pkey->pkey.dh;
 542
 543     return DH_check_ex(dh);
 544 }
 545
 546 static size_t dh_pkey_dirty_cnt(const EVP_PKEY *pkey)
 547 {
 548     return pkey->pkey.dh->dirty_cnt;
 549 }
 550
 551 static void *dh_pkey_export_to(const EVP_PKEY *pk, EVP_KEYMGMT *keymgmt)
 552 {
 553     DH *dh = pk->pkey.dh;
 554     OSSL_PARAM_BLD tmpl;
 555     const BIGNUM *p = DH_get0_p(dh), *g = DH_get0_g(dh), *q = DH_get0_q(dh);
 556     const BIGNUM *pub_key = DH_get0_pub_key(dh);
 557     const BIGNUM *priv_key = DH_get0_priv_key(dh);
 558     OSSL_PARAM *params;
 559     void *provkey = NULL;
 560
 561     if (p == NULL || g == NULL)
 562         return NULL;
 563
 564     ossl_param_bld_init(&tmpl);
 565     if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_FFC_P, p)
 566         || !ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_FFC_G, g))
 567         return NULL;
 568
 569     if (q != NULL) {
 570         if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_FFC_Q, q))
 571             return NULL;
 572     }
 573
 574     /*
 575      * This may be used to pass domain parameters only without any key data -
 576      * so "pub_key" is optional. We can never have a "priv_key" without a
 577      * corresponding "pub_key" though.
 578      */
 579     if (pub_key != NULL) {
 580         if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_DH_PUB_KEY, pub_key))
 581             return NULL;
 582
 583         if (priv_key != NULL) {
 584             if (!ossl_param_bld_push_BN(&tmpl, OSSL_PKEY_PARAM_DH_PRIV_KEY,
 585                                         priv_key))
 586                 return NULL;
 587         }
 588     }
 589
 590     params = ossl_param_bld_to_param(&tmpl);
 591
 592     /* We export, the provider imports */
 593     provkey = evp_keymgmt_importkey(keymgmt, params);
 594
 595     ossl_param_bld_free(params);
 596     return provkey;
 597 }
 598
 599 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
 600     EVP_PKEY_DH,
 601     EVP_PKEY_DH,
 602     0,
 603
 604     "DH",
 605     "OpenSSL PKCS#3 DH method",
 606
 607     dh_pub_decode,
 608     dh_pub_encode,
 609     dh_pub_cmp,
 610     dh_public_print,
 611
 612     dh_priv_decode,
 613     dh_priv_encode,
 614     dh_private_print,
 615
 616     int_dh_size,
 617     dh_bits,
 618     dh_security_bits,
 619
 620     dh_param_decode,
 621     dh_param_encode,
 622     dh_missing_parameters,
 623     dh_copy_parameters,
 624     dh_cmp_parameters,
 625     dh_param_print,
 626     0,
 627
 628     int_dh_free,
 629     dh_pkey_ctrl,
 630
 631     0, 0, 0, 0, 0,
 632
 633     0,
 634     dh_pkey_public_check,
 635     dh_pkey_param_check,
 636
 637     0, 0, 0, 0,
 638
 639     dh_pkey_dirty_cnt,
 640     dh_pkey_export_to,
 641 };
 642
 643 const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
 644     EVP_PKEY_DHX,
 645     EVP_PKEY_DHX,
 646     0,
 647
 648     "X9.42 DH",
 649     "OpenSSL X9.42 DH method",
 650
 651     dh_pub_decode,
 652     dh_pub_encode,
 653     dh_pub_cmp,
 654     dh_public_print,
 655
 656     dh_priv_decode,
 657     dh_priv_encode,
 658     dh_private_print,
 659
 660     int_dh_size,
 661     dh_bits,
 662     dh_security_bits,
 663
 664     dh_param_decode,
 665     dh_param_encode,
 666     dh_missing_parameters,
 667     dh_copy_parameters,
 668     dh_cmp_parameters,
 669     dh_param_print,
 670     0,
 671
 672     int_dh_free,
 673     dhx_pkey_ctrl,
 674
 675     0, 0, 0, 0, 0,
 676
 677     0,
 678     dh_pkey_public_check,
 679     dh_pkey_param_check
 680 };
 681
 682 #ifndef OPENSSL_NO_CMS
 683
 684 static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
 685                               X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
 686 {
 687     const ASN1_OBJECT *aoid;
 688     int atype;
 689     const void *aval;
 690     ASN1_INTEGER *public_key = NULL;
 691     int rv = 0;
 692     EVP_PKEY *pkpeer = NULL, *pk = NULL;
 693     DH *dhpeer = NULL;
 694     const unsigned char *p;
 695     int plen;
 696
 697     X509_ALGOR_get0(&aoid, &atype, &aval, alg);
 698     if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
 699         goto err;
 700     /* Only absent parameters allowed in RFC XXXX */
 701     if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
 702         goto err;
 703
 704     pk = EVP_PKEY_CTX_get0_pkey(pctx);
 705     if (pk == NULL)
 706         goto err;
 707     if (pk->type != EVP_PKEY_DHX)
 708         goto err;
 709     /* Get parameters from parent key */
 710     dhpeer = DHparams_dup(pk->pkey.dh);
 711     /* We have parameters now set public key */
 712     plen = ASN1_STRING_length(pubkey);
 713     p = ASN1_STRING_get0_data(pubkey);
 714     if (p == NULL || plen == 0)
 715         goto err;
 716
 717     if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
 718         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
 719         goto err;
 720     }
 721
 722     /* We have parameters now set public key */
 723     if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
 724         DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
 725         goto err;
 726     }
 727
 728     pkpeer = EVP_PKEY_new();
 729     if (pkpeer == NULL)
 730         goto err;
 731     EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
 732     dhpeer = NULL;
 733     if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
 734         rv = 1;
 735  err:
 736     ASN1_INTEGER_free(public_key);
 737     EVP_PKEY_free(pkpeer);
 738     DH_free(dhpeer);
 739     return rv;
 740 }
 741
 742 static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 743 {
 744     int rv = 0;
 745
 746     X509_ALGOR *alg, *kekalg = NULL;
 747     ASN1_OCTET_STRING *ukm;
 748     const unsigned char *p;
 749     unsigned char *dukm = NULL;
 750     size_t dukmlen = 0;
 751     int keylen, plen;
 752     const EVP_CIPHER *kekcipher;
 753     EVP_CIPHER_CTX *kekctx;
 754
 755     if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
 756         goto err;
 757
 758     /*
 759      * For DH we only have one OID permissible. If ever any more get defined
 760      * we will need something cleverer.
 761      */
 762     if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
 763         DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
 764         goto err;
 765     }
 766
 767     if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
 768         goto err;
 769
 770     if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
 771         goto err;
 772
 773     if (alg->parameter->type != V_ASN1_SEQUENCE)
 774         goto err;
 775
 776     p = alg->parameter->value.sequence->data;
 777     plen = alg->parameter->value.sequence->length;
 778     kekalg = d2i_X509_ALGOR(NULL, &p, plen);
 779     if (!kekalg)
 780         goto err;
 781     kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 782     if (!kekctx)
 783         goto err;
 784     kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
 785     if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
 786         goto err;
 787     if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
 788         goto err;
 789     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
 790         goto err;
 791
 792     keylen = EVP_CIPHER_CTX_key_length(kekctx);
 793     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 794         goto err;
 795     /* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
 796     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
 797                                      OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
 798         <= 0)
 799         goto err;
 800
 801     if (ukm) {
 802         dukmlen = ASN1_STRING_length(ukm);
 803         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 804         if (!dukm)
 805             goto err;
 806     }
 807
 808     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 809         goto err;
 810     dukm = NULL;
 811
 812     rv = 1;
 813  err:
 814     X509_ALGOR_free(kekalg);
 815     OPENSSL_free(dukm);
 816     return rv;
 817 }
 818
 819 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 820 {
 821     EVP_PKEY_CTX *pctx;
 822     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 823
 824     if (pctx == NULL)
 825         return 0;
 826     /* See if we need to set peer key */
 827     if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
 828         X509_ALGOR *alg;
 829         ASN1_BIT_STRING *pubkey;
 830         if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
 831                                                  NULL, NULL, NULL))
 832             return 0;
 833         if (!alg || !pubkey)
 834             return 0;
 835         if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
 836             DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
 837             return 0;
 838         }
 839     }
 840     /* Set DH derivation parameters and initialise unwrap context */
 841     if (!dh_cms_set_shared_info(pctx, ri)) {
 842         DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
 843         return 0;
 844     }
 845     return 1;
 846 }
 847
 848 static int dh_cms_encrypt(CMS_RecipientInfo *ri)
 849 {
 850     EVP_PKEY_CTX *pctx;
 851     EVP_PKEY *pkey;
 852     EVP_CIPHER_CTX *ctx;
 853     int keylen;
 854     X509_ALGOR *talg, *wrap_alg = NULL;
 855     const ASN1_OBJECT *aoid;
 856     ASN1_BIT_STRING *pubkey;
 857     ASN1_STRING *wrap_str;
 858     ASN1_OCTET_STRING *ukm;
 859     unsigned char *penc = NULL, *dukm = NULL;
 860     int penclen;
 861     size_t dukmlen = 0;
 862     int rv = 0;
 863     int kdf_type, wrap_nid;
 864     const EVP_MD *kdf_md;
 865
 866     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 867     if (pctx == NULL)
 868         return 0;
 869     /* Get ephemeral key */
 870     pkey = EVP_PKEY_CTX_get0_pkey(pctx);
 871     if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
 872                                              NULL, NULL, NULL))
 873         goto err;
 874     X509_ALGOR_get0(&aoid, NULL, NULL, talg);
 875     /* Is everything uninitialised? */
 876     if (aoid == OBJ_nid2obj(NID_undef)) {
 877         ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
 878
 879         if (pubk == NULL)
 880             goto err;
 881         /* Set the key */
 882
 883         penclen = i2d_ASN1_INTEGER(pubk, &penc);
 884         ASN1_INTEGER_free(pubk);
 885         if (penclen <= 0)
 886             goto err;
 887         ASN1_STRING_set0(pubkey, penc, penclen);
 888         pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 889         pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 890
 891         penc = NULL;
 892         X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
 893                         V_ASN1_UNDEF, NULL);
 894     }
 895
 896     /* See if custom parameters set */
 897     kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
 898     if (kdf_type <= 0)
 899         goto err;
 900     if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
 901         goto err;
 902
 903     if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
 904         kdf_type = EVP_PKEY_DH_KDF_X9_42;
 905         if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
 906             goto err;
 907     } else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
 908         /* Unknown KDF */
 909         goto err;
 910     if (kdf_md == NULL) {
 911         /* Only SHA1 supported */
 912         kdf_md = EVP_sha1();
 913         if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
 914             goto err;
 915     } else if (EVP_MD_type(kdf_md) != NID_sha1)
 916         /* Unsupported digest */
 917         goto err;
 918
 919     if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
 920         goto err;
 921
 922     /* Get wrap NID */
 923     ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
 924     wrap_nid = EVP_CIPHER_CTX_type(ctx);
 925     if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
 926         goto err;
 927     keylen = EVP_CIPHER_CTX_key_length(ctx);
 928
 929     /* Package wrap algorithm in an AlgorithmIdentifier */
 930
 931     wrap_alg = X509_ALGOR_new();
 932     if (wrap_alg == NULL)
 933         goto err;
 934     wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
 935     wrap_alg->parameter = ASN1_TYPE_new();
 936     if (wrap_alg->parameter == NULL)
 937         goto err;
 938     if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
 939         goto err;
 940     if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
 941         ASN1_TYPE_free(wrap_alg->parameter);
 942         wrap_alg->parameter = NULL;
 943     }
 944
 945     if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
 946         goto err;
 947
 948     if (ukm) {
 949         dukmlen = ASN1_STRING_length(ukm);
 950         dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
 951         if (!dukm)
 952             goto err;
 953     }
 954
 955     if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
 956         goto err;
 957     dukm = NULL;
 958
 959     /*
 960      * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
 961      * of another AlgorithmIdentifier.
 962      */
 963     penc = NULL;
 964     penclen = i2d_X509_ALGOR(wrap_alg, &penc);
 965     if (penc == NULL || penclen == 0)
 966         goto err;
 967     wrap_str = ASN1_STRING_new();
 968     if (wrap_str == NULL)
 969         goto err;
 970     ASN1_STRING_set0(wrap_str, penc, penclen);
 971     penc = NULL;
 972     X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
 973                     V_ASN1_SEQUENCE, wrap_str);
 974
 975     rv = 1;
 976
 977  err:
 978     OPENSSL_free(penc);
 979     X509_ALGOR_free(wrap_alg);
 980     return rv;
 981 }
 982
 983 #endif